With the development of a wide variety of infrared radiation sources, infrared radiation is being increasingly utilized for communications and signaling purposes. Infrared receiving devices have primarily consisted of semiconductors having relatively narrow bandgaps. These devices are relatively slow and cannot be used in high data rate transmissions appropriate to light communications. Conversely, contemporary high speed photomultipliers, such as those made of GaAs, lose their response in the infrared region. It would, therefore, be desirable to provide a high-speed optical upconverter that will change incoming infrared signals into shorter wavelengths so that the potential of high-speed solid state photomultipliers could utilized. It is generally desirable to provide a device that is capable of optical upconversion for all those situations where a change in light wavelength is beneficial.